1. Field of Invention
The present invention relates to a system and a method for controlling an electrically-powered steering apparatus of a vehicle, and more particularly to a system and a method for controlling an electrically-powered steering apparatus of a vehicle which can control a steering force of the vehicle.
2. Description of Related Art
Generally, a steering apparatus is mounted for changing a moving direction of a vehicle, and includes an operating apparatus delivering a force operating a steering handle by a driver to a steering gear, a gear apparatus reducing a rotational speed of a steering shaft and changing a movement direction of the operating apparatus, and a link apparatus delivering the movement of the gear apparatus to a front left wheel and a front right wheel and keeping a constant relation of the wheels.
Such the steering apparatus is not easy to change the moving direction of the vehicle by a force of a driver only. Therefore, a power steering apparatus is used to assist the steering force changing the moving direction of the vehicle. The power steering apparatus is adapted to convert hydraulic pressure into mechanical force or use a power of a motor so as to assist the steering force.
Particularly, when the steering force is assisted by the power of the motor, the steering force can be controlled according to a speed of the vehicle by changing a current transmitted to the motor. Therefore, such power steering apparatus is so configured that the steering force is controlled to be light at a low speed so as to lighten an steering effort of the driver, and to be heavy at a high speed so as to make the driver feel comfortable.
Recently, various steering modes for changing the steering force has been provided so as to satisfy various demands of the driver. In further detail, different steering forces are generated according to a driving region of the vehicle, a demand of the driver and so on at various steering modes. And, the steering force is controlled according to the speed of the vehicle at each steering mode.
However, the number of the steering modes provided in one vehicle is restricted to the specific number. That is, the specific number of the steering modes is provided based on a data obtained by supposing the driving region of the vehicle and the demand of the driver. The specific steering modes is predetermined in the vehicle. Therefore, the steering force cannot be changed variously according to the drive state of the vehicle or the demand of the driver at the predetermined steering modes when the vehicle is driven actually.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.